Application of the ONIOM method to enantioselective deprotonation in the presence of spartein

The hybrid ONIOM method has been tested for enantioselective deprotonation reaction of N-Boc-pyrrolidine and N-Boc-piperidine using isopropyl-lithium in the presence of sparteine. This study investigates different partitions and level of theories of ONIOM method, while the results are reported with regular DFT and ONIOM calculations. The system requires partitioning into layers that are not ideal for ONIOM, and we assess the effect of the various places where the border region can be placed.